06/01/2014 11:16 am ET Updated Jun 01, 2014

Some Substance Use, Mental Conditions Have Similar Death Risks As Heavy Smoking

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A new review of studies shows just how some substance use disorders and mental conditions affect lifespan —- and depending on the condition, the mortality risks are the same, if not higher, than heavy smoking.

“We found that many mental health diagnoses are associated with a drop in life expectancy as great as that associated with smoking 20 or more cigarettes a day,” study researcher Dr. Seena Fazel, of the Department of Psychiatry at Oxford University, said in a statement. Fazel noted that some possible reasons include the association between people with mental health issues and high-risk behaviors (such as drug and alcohol abuse), as well as potential barriers to proper health care for people experiencing mental health issues.

The review, published in the journal World Psychiatry, included 20 systematic reviews and meta-analyses that in turn included data from more than 1.7 million people with mental disorders, as well as more than 250,000 deaths. The researchers further examined 14 publications with data on life expectancy.

They found that the loss of years of life among heavy smokers is between eight and 10 years. Comparably, the loss of years of life is between nine and 20 years for people with bipolar disorder, between 10 and 20 years for people with schizophrenia, and between seven and 11 years for people with recurrent depression, according to the review.

The potential lost years of life for substance use disorders was even higher -- between nine and 24 years for people with drug and alcohol abuse problems.

The rate of death from suicide was higher than the general public for some conditions, including borderline personality disorder, depression, bipolar disorder, schizophrenia and opioid use, the review showed.

“Smoking has been an important target for prevention because it is so common and perceived to be so dangerous. Mental disorders are also relatively common when considered together, but the risk to life is not perceived in the same way,“ the researchers wrote in the study. “From a public health perspective, patients with serious mental illness should be designated as a high risk population for physical illness, given the substantial health disparities compared with the general population.”